o-anisidine

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Additional information

There are no studies available on reproductive toxicity for o-anisidine.

Observations of histopathological examinations of the NCI (1978) two year carcinogenicity study (test item: o-anisidine hydrochloride) with mice and rats showed no effects on the male and female reproductive organs (examinations included: seminal vesicles, prostate, and testis in males; ovary and uterus in females).

In a 28 day repeated dose toxicity study (test item: o-anisidine; oral application) with male and female rats no effects on the testes were seen (female organs were not examined).

The EU-RAR concluded that these data do not indicate that o-anisidine impairs reproduction.

Short description of key information:
There are no information on toxicity of o-anisidine to reproduction. Data on related substances indicate that o-anisidine does not impair fertility.

Effects on developmental toxicity

Description of key information

There are no information on developmental toxicity of o-anisidine. The EU-RAR concluded that due to positive evidence from related substances, "o-anisidine may be suspected to possess teratogenic properties."

Additional information

There are no information on developmental toxicity of o-anisidine. Data on developmental toxicity and teratogenicity of structurally related substances to o-anisidine are discussed in the EU-RAR:

o-Aminophenol, a known metabolite of o-anisidine, revealed embryotoxic and teratogenic properties investigated in the syrian hamster (i.p.application of 100 mg/kg bw; no maternal toxicity was observed at this dose).

p-Aminophenol, a structurally less related substance, showed clearly teratogenic and developmental toxic effects. For example in several studies after oral application in rats (no statements given whether there was maternal toxicity observed) as well as in hamster after i.p. or i.v. application in the absence of toxicity to the dams.

There is also evidence for developmental toxicity and teratogenicity of aniline.

In the RAR it is concluded that the effects from aniline can be compared to the expected effects for o-anisidine as both substances cause methaemoglobinemia. The methaemoglobin formation observed in animals treated with aromatic amines in general may affect the developing organisms of the offsprings even more than the dams. Genotoxicity may also be responsible for the damaging effects in early stages of the developing offspring (both o- and p-aminophenol are classified as Cat. 3 mutagens). But the evidence for genotoxic potential of o-anisidine from the in vivo genotoxicity tests is not convincing.

Justification for classification or non-classification

There are no data on reproductive toxicity of o-anisidine available. The EU-RAR concluded that existing data on related substances indicate that o-anisidine does not impair fertility but may be suspected to posses teratogenic properties. However, a final conclusion on classification of o-anisidine for toxicity to reproduction cannot be drawn from these data.